In the New York TImes, Leslie Kaufman says,
“Story collections, an often underappreciated literary cousin of novels, are experiencing a resurgence, driven by a proliferation of digital options that offer not only new creative opportunities but exposure and revenue as well.”
The resurgence of short stories as a viable book form has been growing steadily for the past three  years. A combination of factors impacts this trend.
First, publishers have been adding more short story collections to their catalogs because they recognize that a portion of dedicated readers want to be able to pick up a book for a shorter period. Reading one short story in a collection allows them to read for a brief time. They return later, sometimes much later, to the same story collection without having lost the threads they have to remember when reading novels.
Second, stories can be marketed directly to readers through programs like Amazon’s shorts. Publishing a short story as a single download allows readers to sample an author’s work…thus having the added benefit of potentially driving new readers to their novels.
Third, although the internet allows for individual stories to reach certain audiences, they are still within the walls of that magazine’s readership. Collections and single downloads can reach broader audiences.
Finally, short stories have traditionally had an upper limit that doesn’t necessarily serve every story. Electronic publishing of singles and print publishing of collections allows for very long short stories that might otherwise never be published to be disseminated.